U.S. patent number 10,006,354 [Application Number 14/326,382] was granted by the patent office on 2018-06-26 for system and method for variable tongue spacing in a multi-channel turbine in a charged internal combustion engine.
This patent grant is currently assigned to Ford Global Technologies, LLC. The grantee listed for this patent is Ford Global Technologies, LLC. Invention is credited to Joerg Kemmerling, Helmut Matthias Kindl, Andreas Kuske, Norbert Andreas Schorn, Vanco Smiljanovski, Franz Arnd Sommerhoff.
United States Patent |
10,006,354 |
Kindl , et al. |
June 26, 2018 |
System and method for variable tongue spacing in a multi-channel
turbine in a charged internal combustion engine
Abstract
An internal combustion engine comprising a dual flow
turbocharger includes an annular support with at least one
tongue-like end wherein the annular support is adjustable in a
translational fashion along the turbines axis of rotation. Moving
the annular support influences the degree of separation behavior of
turbine channels by varying a tongue spacing to the rotor.
Inventors: |
Kindl; Helmut Matthias (Aachen,
DE), Schorn; Norbert Andreas (Aachen, DE),
Smiljanovski; Vanco (Bedburg, DE), Sommerhoff; Franz
Arnd (Aachen, DE), Kuske; Andreas (Geulle,
NL), Kemmerling; Joerg (Monschau, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Ford Global Technologies, LLC |
Dearborn |
MI |
US |
|
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Assignee: |
Ford Global Technologies, LLC
(Dearborn, MI)
|
Family
ID: |
52254320 |
Appl.
No.: |
14/326,382 |
Filed: |
July 8, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20150013330 A1 |
Jan 15, 2015 |
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Foreign Application Priority Data
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Jul 9, 2013 [DE] |
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10 2013 213 450 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02B
37/025 (20130101); F02B 37/22 (20130101); F01D
9/026 (20130101); F02B 37/24 (20130101); Y02T
10/144 (20130101); Y02T 10/12 (20130101); F05D
2220/40 (20130101) |
Current International
Class: |
F02B
37/24 (20060101); F02B 37/02 (20060101); F02B
37/22 (20060101); F01D 9/02 (20060101) |
Field of
Search: |
;60/602 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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101473117 |
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Jul 2009 |
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CN |
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102080577 |
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Jun 2011 |
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CN |
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102619617 |
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Aug 2012 |
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CN |
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4232400 |
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Aug 1993 |
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DE |
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10028733 |
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Dec 2001 |
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DE |
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102008039085 |
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Feb 2010 |
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DE |
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102009012131 |
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Sep 2010 |
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DE |
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2349179 |
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Oct 2000 |
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GB |
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2012107064 |
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Aug 2012 |
|
WO |
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Other References
State Intellectual Property Office of the People's Republic of
China, Office Action Issued in Application No. 201410324044.X,
dated Nov. 16, 2017, 10 pages. (Submitted with Partial
Translation). cited by applicant.
|
Primary Examiner: Newton; Jason T
Attorney, Agent or Firm: Voutyras; Julia McCoy Russell
LLP
Claims
The invention claimed is:
1. A method for operating a charged engine, comprising: determining
engine operating conditions, and when conditions are below a
threshold, displacing an annular support in a translational fashion
along a rotatable shaft of a turbine from a rest position to a
first working position, wherein in the first working position at
least one tongue element of the support abuts against and lengthens
a free tongue-like end of a turbine housing wall that separates two
adjacent channels of the turbine from one another.
2. The method as claimed in claim 1, wherein the support is
transferred into the first working position in response to an
engine speed less than a threshold speed, and wherein the support
is transferred into the rest position in response to an engine
speed greater than the threshold speed.
3. The method as claimed in claim 2, further comprising
transferring the support into the first working position in
response to an engine load less than a threshold load, and
transferring the support into the rest position in response to an
engine load greater than the threshold load.
4. The method as claimed in claim 1, wherein in the rest position
of the support, a flow transfer duct at the free tongue-like end of
the housing wall is open and the two adjacent channels are
connected via the flow transfer duct, and wherein in the first
working position of the support, the flow transfer duct is closed
and the two adjacent channels are separated from one another such
that each channel communicates only with exhaust lines of an engine
cylinder group from which each channel is fed.
5. The method as claimed in claim 1, wherein in the rest position
of the support, the at least one tongue element is positioned
laterally adjacent to a rotor of the turbine.
6. A method for adjusting a charger, comprising: responsive to an
engine speed less than a threshold, closing a flow transfer duct at
a free tongue-like end of a housing wall of a turbine by moving a
tongue-like element of an annular support into an exhaust flow to
abut against the free tongue-like end of the housing wall; and
responsive to an engine speed greater than the threshold, adjusting
the annular support to open the flow transfer duct.
7. The method of claim 6, wherein the annular support is adjusted
in a continuously variable fashion via an electronic engine
controller coupled to an engine.
8. The method of claim 6, wherein adjusting the annular support to
open the flow transfer duct includes moving the tongue-like element
of the annular support into a housing of the turbine, the housing
including the housing wall, wherein the tongue-like dement is
positioned laterally adjacent to a rotor of the turbine.
9. The method of claim 6, wherein the annular support is adjusted
in a translational fashion along the turbine's axis of
rotation.
10. The method of claim 6, wherein the housing wall separates two
adjacent channels of the turbine from one another, wherein when the
flow transfer duct is open the two adjacent channels are connected
via the flow transfer duct, and wherein when the flow transfer duct
is closed the two adjacent channels are separated from one another
such that each channel communicates only with exhaust lines of an
engine cylinder group from which each channel is fed.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority to German Patent
Application No. 102013213450.9, filed Jul. 9, 2013, the entire
contents of which are hereby incorporated by reference for all
purposes.
BACKGROUND\SUMMARY
An engine charged with a turbocharger comprising a multi-channel
turbine includes a wall which separates the channels to an extent
to the rotor to vary the interaction between the two channels. A
dual flow turbine is able to separate two flows of two cylinder
exhaust groups, which helps to improve low end torque. The
efficiency and the separation characteristic of dual flow turbines
are influenced by the spacing distance between the tongue of the
turbine housing wall and the turbine wheel. The engine may consider
different spacing characteristics of the turbine in different
operating conditions to increase efficiency.
One approach is to provide a wall which separates the channels from
one another to the rotor, at low engine speeds/loads this aids in
pulse charging. Another approach is to provide a wall which leaves
spacing to the rotor, thereby providing a degree of interaction
between the two channels, at high engine speeds/load this aids in
constant pressure charging.
A potential issue noted by the inventors with the above approaches
is that providing a wall which has a fixed position only enables
the engine to be optimized under certain operating conditions.
One potential approach to at least partially address some of the
above issues includes a charged internal combustion engine
comprising at least one cylinder head with at least two cylinders
and at least one exhaust-gas turbocharger with at least one
turbine. Each cylinder of the charged internal combustion engine
comprises at least one outlet opening for discharging the exhaust
gases out of the cylinder with each outlet opening being adjoined
by an exhaust line. The at least two cylinders are configured in
such a way as to form at least two groups with in each case at
least one cylinder. The exhaust lines of the cylinders of each
cylinder group merge to form a respective overall exhaust line,
thus forming an exhaust manifold with the at least two overall
exhaust lines being connected to a multi-channel segmented turbine.
The turbine comprises at least one rotor mounted on a rotatable
shaft in a turbine housing and the at least two channels of the
turbine, when viewed in a section perpendicular to the shaft of the
rotor are arranged one on top of the other at least along an
arc-shaped section and enclose the at least one rotor in spiral
form at different radii and are open toward the at least one rotor
in each case along a circular-arc-shaped segment, in such a way
that in each case one overall exhaust line is connected to one of
the at least two channels of the turbine. In each case, the two
adjacent channels are separated from one another, at least in
sections and in a continuation of the overall exhaust lines in the
turbine housing by means of a housing wall. At the rotor side, the
at least one housing wall that separates two adjacent channels has
a free tongue-like end and ends with a spacing to the at least one
rotor, such that a tongue spacing is formed. Here, the
multi-channel segmented turbine is the turbine of the at least one
exhaust-gas turbocharger wherein a movable annular support is
provided which has at least one tongue-like element and which is
displaceable in translational fashion along the rotatable shaft for
the purpose of varying the tongue spacing. When the support is in a
first working position, the at least one tongue-like element
lengthens the free tongue-like end of the housing wall that
separates two adjacent channels such that the tongue spacing is
reduced to the at least one rotor. When the support is in a rest
position, the at least one tongue-like element is positioned
laterally adjacent to the at least one rotor.
In this way, a multi-channel turbocharger with adjustable tongue
spacing may vary the degree of interaction between the channels via
the tongue spacing. Thus, a flow transfer duct may be opened or
closed based on engine operating parameters to change the degree of
separation of the channels to the rotor and better enable operating
at different conditions. For example, at high engine loads and/or
speeds, when a large exhaust gas volume may be present in the
exhaust manifold, the degree of interaction between the channels
may be high by adjusting the annular support to open a flow
transfer duct. In another example, at a low engine load, when a
small exhaust gas volume is present, the tongue spacing may be
lengthened by adjusting the annular support to close a flow
transfer duct and increase the degree of separation of the
channels.
In another example, a method for operating a charged engine,
comprises displacing an annular support with at least one
tongue-like element in a translational fashion along a rotatable
shaft of a turbine from a rest position to a first working position
in order to increase a degree of separation of at least two
channels of the turbine by reducing a tongue spacing. In this way,
by reducing the tongue spacing, it is possible to decrease the
degree of interaction of the two channels to the turbine under
engine operating conditions where a difference in exhaust flow in
the two channels may exist. Thus, mutual influencing of the
pressure pulses of the exhaust flow may be substantially reduced
and turbine efficiency increased.
It should be understood that the summary above is provided to
introduce in simplified form a selection of concepts that are
further described in the detailed description. It is not meant to
identify key or essential features of the claimed subject matter,
the scope of which is defined uniquely by the claims that follow
the detailed description. Furthermore, the claimed subject matter
is not limited to implementations that solve any disadvantages
noted above or in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example embodiment of a multi-cylinder
charged engine with a turbocharger.
FIG. 2 schematically shows the two-channel turbine of a first
embodiment of the charged internal combustion engine sectioned
perpendicularly to the axis of rotation with an annular
support.
FIG. 3a schematically shows the two-channel turbine of a first
embodiment of the charged internal combustion engine, sectioned
perpendicularly to the axis of rotation of the rotor, and with a
support situated in the rest position.
FIG. 3b schematically shows the turbine illustrated in FIG. 3a in a
section rotated through 90.degree. with respect to FIG. 3a.
FIG. 3c schematically shows the two-channel turbine of a first
embodiment of the charged internal combustion engine, sectioned
perpendicularly with respect to the axis of rotation of the rotor,
and with the support situated in the first working position.
FIG. 3d schematically shows the turbine illustrated in FIG. 3c in a
section rotated through 90.degree. with respect to FIG. 3c.
FIG. 4a schematically shows the annular support as a one piece
construction.
FIG. 4b schematically shows the annular support as a multi-piece
construction.
FIG. 5 illustrates an example method for transferring the annular
support in response to engine speed and load.
DETAILED DESCRIPTION
The present application relates to a charged internal combustion
engine, for example a supercharged engine, comprising at least one
cylinder head with at least two cylinders and having at least one
exhaust-gas turbocharger with at least one turbine, wherein each
cylinder has at least one outlet opening for discharging the
exhaust gases out of the cylinder and each outlet opening is
adjoined by an exhaust line. The at least two cylinders are
configured in such a way as to form at least two groups with in
each case at least one cylinder. The exhaust lines of the cylinders
of each cylinder group merge to form a respective overall exhaust
line, thus forming an exhaust manifold with the at least two
overall exhaust lines being connected to a multi-channel segmented
turbine. The turbine comprises at least one rotor mounted on a
rotatable shaft in a turbine housing and the at least two channels
of the turbine--as viewed in a section perpendicular to the shaft
of the rotor--are arranged one on top of the other at least along
an arc-shaped section and enclose the at least one rotor in spiral
form at different radii and are open toward the at least one rotor
in each case along a circular-arc-shaped segment, in such a way
that in each case one overall exhaust line is connected to one of
the at least two channels of the turbine. The two adjacent channels
are separated from one another, at least in sections and in a
continuation of the overall exhaust lines in the turbine housing,
by means of a housing wall, wherein, at the rotor side, the at
least one housing wall that separates two adjacent channels has a
free tongue-like end and ends with a spacing to the at least one
rotor, such that a tongue spacing is formed. The multi-channel
segmented turbine is the turbine of the at least one exhaust-gas
turbocharger.
The present application also relates to a method for operating an
internal combustion engine of said type.
An internal combustion engine of the type mentioned in the
introduction is used as a motor vehicle drive unit. Within the
context of the present application, the expression "internal
combustion engine" encompasses diesel engines and applied-ignition
engines and also hybrid internal combustion engines, which utilize
a hybrid combustion process, and hybrid drives which comprise not
only the internal combustion engine but also an electric machine
which is connected in terms of drive to the internal combustion
engine and which receives power from the internal combustion engine
or which, as a switchable auxiliary drive, outputs additional
power.
Internal combustion engines have a cylinder block and a cylinder
head which are connected to one another to form the cylinders. The
cylinder head conventionally serves to hold the valve drive. To
control the charge exchange, an internal combustion engine requires
control elements--generally in the form of valves--and actuating
devices for actuating these control elements. The valve actuating
mechanism for the movement of the valves, including the valves
themselves, is referred to as the valve drive. During the charge
exchange, the combustion gases are discharged via the outlet
openings of the at least two cylinders, and the charging of the
combustion chambers, that is to say the induction of fresh mixture
or charge air, takes place via the inlet openings.
In some approaches, the exhaust lines which adjoin the outlet
openings are at least partially integrated in the cylinder head and
are merged to form a common overall exhaust line or in groups to
form two or more overall exhaust lines. The merging of exhaust
lines to form an overall exhaust line is referred to generally, and
within the context of the present application, as an exhaust
manifold.
The way in which the exhaust lines of the cylinders are merged in
the specific situation, that is to say the design configuration of
the exhaust-gas discharge system, is dependent substantially on the
characteristic map areas for which the operating behavior of the
internal combustion engine is to be optimized.
In the case of charged internal combustion engines in which at
least one turbine of an exhaust-gas turbocharger is provided in the
exhaust-gas discharge system and which are intended to exhibit
satisfactory operating behavior in the lower engine speed and/or
load range, that is to say in the case of relatively low
exhaust-gas flow rates, so-called pulse charging, also known as
impulse supercharging, is selected.
Here, the dynamic wave phenomena which occur in the exhaust-gas
discharge system--in particular during the charge exchange--should
be utilized for the purpose of charging and for improving the
operating behavior of the internal combustion engine.
The evacuation of the combustion gases out of a cylinder of the
internal combustion engine during the charge exchange is based
substantially on two different mechanisms. When the outlet valve
opens close to bottom dead center at the start of the charge
exchange, the combustion gases flow at high speed through the
outlet opening into the exhaust-gas discharge system on account of
the high pressure level prevailing in the cylinder at the end of
the combustion and the associated high pressure difference between
the combustion chamber and exhaust line. Said pressure-driven flow
process is assisted by a high pressure peak which is also referred
to as a pre-outlet shock and which propagates along the exhaust
line at the speed of sound, with the pressure being dissipated,
that is to say reduced, to a greater or lesser extent with
increasing distance traveled as a result of friction.
During the further course of the charge exchange, the pressures in
the cylinder and in the exhaust line are equalized, such that the
combustion gases are no longer evacuated primarily in a
pressure-driven manner but rather are discharged as a result of the
reciprocating movement of the piston.
At low engine speeds, the pre-outlet shock may advantageously be
utilized for pulse charging, wherein temporally short, high
pressure pulses may be utilized for energy utilization in the
turbine. In this way, it is possible by means of exhaust-gas
charging, for example turbocharging, to generate high
charge-pressure ratios, that is to say high charge pressures on the
inlet side, even in the case of low exhaust-gas flow rates, in
particular at low engine speeds.
Pulse charging has proven to be particularly advantageous for
accelerating the turbine rotor, that is to say for increasing the
turbine rotational speed, which may fall to a noticeable extent
during idle operation of the internal combustion engine or at low
load, and which should frequently be increased again with as little
delay as possible by means of the exhaust-gas flow in the event of
an increased load demand. The inertia of the rotor and the friction
in the shaft bearing arrangement generally slow an acceleration of
the rotor to higher rotational speeds and therefore hinder an
immediate rise in the charge pressure.
To be able to utilize the dynamic wave phenomena occurring in the
exhaust-gas discharge system, in particular the pre-outlet shocks,
for the pulse charging for improving the operating behavior of the
internal combustion engine, the pressure peaks or pre-outlet shocks
in the exhaust-gas discharge system must be maintained. It is
particularly advantageous if the pressure impulses are intensified
in the exhaust lines, but at least do not attenuate one another or
cancel one another out.
It is therefore expedient for the cylinders to be grouped, or for
the exhaust lines to be merged, in such a manner that the high
pressures, in particular the pre-outlet shocks of the individual
cylinders, in the exhaust-gas discharge system are maintained, and
mutual influencing may be substantially reduced.
The subject matter of the present application also encompasses an
internal combustion engine in which the cylinders are grouped.
According to the present application, at least two cylinders are
configured in such a way as to form at least two groups with in
each case at least one cylinder. The exhaust lines of the cylinders
of each cylinder group merge to form a respective overall exhaust
line, thus forming an exhaust manifold. Here, the cylinders are
configured in such a way that the dynamic wave phenomena in the
exhaust lines of the cylinders of a group have the least possible
adverse effect on one another.
In a cylinder head having four cylinders in an in-line arrangement,
it is advantageous in this regard for two cylinders which have an
ignition interval of 360.degree. CA to be combined in each case to
form a cylinder group. For example, if the ignition in the
cylinders is initiated in accordance with the ignition sequence
1-2-4-3 or in accordance with the ignition sequence 1-3-4-2, it is
advantageous for the outer cylinders to be combined to form a first
group and for the inner cylinders to be combined to form a second
group.
Pulse charging however also has disadvantages. For example, the
charge exchange is generally impaired as a result of the pressure
pulses in the exhaust-gas discharge system. The cylinders of a
group may have an interfering, that is to say detrimental effect on
one another during the charge exchange. The pressure waves
originating from a cylinder run through the at least one exhaust
line of said cylinder and also along the exhaust lines of the other
cylinders of said group, specifically possibly as far as the outlet
opening provided at the end of the respective line. Exhaust gas
which has already been expelled or discharged into an exhaust line
during the charge exchange may thus pass back into the cylinder
again, specifically as a result of the pressure wave originating
from another cylinder. In particular, it has proven to be
disadvantageous if, toward the end of the charge exchange, positive
pressure prevails at the outlet opening of a cylinder or the
pressure wave of another cylinder propagates along the exhaust line
in the direction of the outlet opening, as this counteracts the
evacuation of the combustion gases out of said cylinder. In said
phase of the charge exchange, the combustion gases are discharged
primarily owing to the reciprocating movement of the piston. In
individual situations, it may even be the case that exhaust gas
originating from one cylinder passes into another cylinder before
the outlet thereof closes. The exhaust gas situated in the
cylinder, that is to say the residual gas fraction remaining in the
cylinder, has a significant influence on the knocking behavior of
an applied-ignition internal combustion engine, wherein the risk of
knocking combustion rises with increasing exhaust-gas fraction.
It is also taken into consideration that a turbine is operated most
effectively without shocks and without being subjected to
fluctuating partial loads. To enable a turbine which is provided
downstream of the cylinders in the exhaust-gas discharge system to
be operated optimally at relatively high engine speeds, the turbine
should be acted on with as constant an exhaust-gas pressure as
possible, for which reason a pressure which varies as little as
possible is preferable upstream of the turbine rotor in order to
realize so-called constant pressure charging, also known as ram
supercharging.
By means of a correspondingly large exhaust-gas volume upstream of
the rotor, the pressure pulsations in the exhaust lines may be
smoothed. In this respect, the grouping of the cylinders, whereby
the exhaust lines are combined in groups, resulting in the volume
of the exhaust-gas discharge system upstream of the turbine rotor
being divided into a plurality of partial volumes, has proven to be
counterproductive.
With regard to constant pressure charging, it may be rather
advantageous for the exhaust lines of all the cylinders to be
merged into a single overall exhaust line in order to make the
exhaust-gas volume of the exhaust-gas discharge system upstream of
a turbine which is arranged in said overall exhaust line as large
as possible, that is to say to maximize said exhaust-gas volume,
and to minimize the pressure fluctuations.
There is thus a resulting conflict of aims when configuring the
exhaust-gas discharge system for the purpose of optimizing the
exhaust-gas discharge system both with regard to low engine speeds
and with regard to high engine speeds. Grouping the cylinders in
order to realize pulse charging leads to an expedient operating
behavior at low engine speeds, but disadvantages must be accepted
at relatively high engine speeds. In contrast, if as large an
exhaust-gas volume as possible is realized upstream of the turbine
in order to be able to utilize the advantages of constant pressure
charging, the operating behavior at low engine speeds is
impaired.
Concepts are known from some approaches in which the two exhaust
manifolds of the two cylinder groups may be connected to and
separated from one another. The exhaust-gas discharge system is
then configured as a function of the engine speed, such that
charging of the engine by pulse charging may be realized by
separating the exhaust manifolds and charging of the engine by
constant pressure charging may be realized by connecting the
exhaust manifolds.
A disadvantage of the concept described above is that, as a result
of the connection of the manifolds, a connection is realized close
to the outlet openings of the cylinders, whereby the residual gas
problem described above, and the associated knocking problem, is
abetted.
Concepts are likewise known in which the channels of the
multi-channel turbine may be connected to one another and separated
from one another in the turbine housing, wherein the channels are
connected to one another and separated from one another as a
function of engine speed in order for the internal combustion
engine to be operated, and charged, by means of pulse charging and
constant pressure charging respectively.
Aside from the strict separation and complete connection of the
manifolds or of the channels, concepts or turbines may also be of
interest in which the degree of interaction between the channels of
the turbine, and thus the separation behavior of the turbine
channels, may be influenced.
It may then be possible, over virtually the entire characteristic
map of the internal combustion engine, for the turbine to be
adapted to an extremely wide variety of operating points or
operating conditions in order to better enable operation of the
internal combustion engine with the greatest possible level of
optimization with regard to fuel consumption and with the lowest
possible emissions.
Against the background of that stated above, it is an object of the
present application to provide a charged, e.g. supercharged,
internal combustion engine as per the preamble of claim 1, in which
the degree of interaction between the channels of the turbine, and
the separation behavior of the channels, that is to say the degree
of separation, may be influenced.
It is a further sub-object of the present application to specify a
method for operating an internal combustion engine of said
type.
The first sub-object is achieved by means of a charged internal
combustion engine having at least one cylinder head with at least
two cylinders and having at least one exhaust-gas turbocharger with
at least one turbine. Each cylinder has at least one outlet opening
for discharging the exhaust gases out of the cylinder, and each
outlet opening is adjoined by an exhaust line with the at least two
cylinders configured in such a way as to form at least two groups
with in each case at least one cylinder. The exhaust lines of the
cylinders of each cylinder group merge to form a respective overall
exhaust line, thus forming an exhaust manifold. The at least two
overall exhaust lines are connected to a multi-channel segmented
turbine, which comprises at least one rotor mounted on a rotatable
shaft in a turbine housing and the at least two channels of
which--as viewed in a section perpendicular to the shaft of the
rotor--are arranged one on top of the other at least along an
arc-shaped section and enclose the at least one rotor in spiral
form at different radii and are open toward the at least one rotor
in each case along a circular-arc-shaped segment, in such a way
that in each case one overall exhaust line is connected to one of
the at least two channels of the turbine with in each case two
adjacent channels are separated from one another, at least in
sections and in a continuation of the overall exhaust lines in the
turbine housing, by means of a housing wall, wherein, at the rotor
side, the at least one housing wall that separates two adjacent
channels has a free tongue-like end and ends with a spacing to the
at least one rotor, such that a tongue spacing is formed. The
multi-channel segmented turbine is the turbine of the at least one
exhaust-gas turbocharger and wherein a movable annular support is
provided which has at least one tongue-like element and which is
displaceable in translational fashion along the rotatable shaft for
the purpose of varying the tongue spacing, wherein, when the
support is in a first working position the at least one tongue-like
element lengthens the free tongue-like end of a housing wall that
separates two adjacent channels, such that the tongue spacing is
reduced, and when the support is in a rest position, the at least
one tongue-like element is positioned laterally adjacent to the at
least one rotor.
In the internal combustion engine according to the present
application, two adjacent channels of the turbine are connected or
connectable to one another at their rotor-side end by means of a
flow transfer duct, wherein the flow cross section of the flow
transfer duct and thus the degree of interaction between the
channels may be influenced through a variation of the tongue
spacing. Here, the tongue spacing is defined as the spacing between
the free tongue-like end of the housing wall, which separates the
adjacent channels from one another, and the at least one rotor, or
as the spacing between the end of a tongue-like element of an
annular support, which, at least when the support is in a first
working position, lengthens the free tongue-like end of a housing
wall that separates two adjacent channels, and the at least one
rotor.
The present application is focused on the interaction between the
channels or on the influencing of said interaction and the
variation of the degree of said interaction, and not on the
transition from constant pressure charging to pulse charging or
vice versa.
The first object on which the present application is based is thus
achieved, that is to say a charged internal combustion engine as
per the preamble of claim 1 is provided in which the degree of
interaction between the channels of the turbine may be
influenced.
Nevertheless, embodiments may be realized in which, when the
annular support is in the first working position, adjacent channels
of the turbine and thus the exhaust systems of the associated
cylinder groups are separated from one another, such that each
channel communicates only with the exhaust lines of that cylinder
group from which it is originally fed. This assists pulse charging
utilizing the pressure peaks propagating into the exhaust
manifolds. When the support is in the rest position, an exchange of
exhaust gas may then be possible between the adjacent channels via
the flow transfer duct. It may be possible for the pressure
fluctuations in the channels of the turbine to be smoothed, or for
the pressures in the channels upstream of the rotor to be aligned,
as a function of the degree of interaction between the channels. A
specific objective could be specified for the individual
situation.
Multi-channel turbines are suitable for charged internal combustion
engines in which the exhaust lines of the cylinders are merged in
groups, in order to realize channel separation and in order to
reduce interaction between the channels, but also for internal
combustion engines with partial deactivation capability, in which
one cylinder group is configured as a switchable cylinder group and
in which, if appropriate, the channel of a deactivated cylinder
group should likewise be able to be deactivated, that is to say
closed off.
The turbine may fundamentally be fitted with a variable turbine
geometry which may be adapted by adjustment to the respective
operating point of the internal combustion engine.
In the internal combustion engine according to the present
application, the exhaust lines of at least two cylinders are merged
to form at least two overall exhaust lines, thus forming at least
two exhaust manifolds. In this respect, embodiments having three,
four, five or more cylinders, wherein the exhaust lines of more
than two cylinders are merged to form two or more overall exhaust
lines, are likewise internal combustion engines according to the
present application, wherein then, use could be made of a
three-channel, four-channel or five-channel turbine.
Further advantageous embodiments of the internal combustion engine
according to the present application will be explained in
conjunction with the subclaims.
Embodiments of the charged internal combustion engine are
advantageous in which the support is adjustable in two-stage
fashion and is situated either in the first working position or in
the rest position.
The control of the support is simplified if the support is
configured so as to be switchable in two-stage fashion such that
either a housing wall that separates two adjacent channels is
lengthened at its free tongue-like end by the at least one
tongue-like element or else said at least one tongue-like element
is positioned laterally adjacent to the at least one rotor. This
offers cost advantages in particular.
The support may however also be switchable in continuously variable
fashion such that the at least one tongue-like element lengthens
the housing wall along a section of the free tongue-like end
thereof, and a remaining section is not lengthened, that is to say
remains non-lengthened, and maintains its original extent. The
number of degrees of freedom for influencing the interaction
between the channels of the turbine is increased considerably.
Embodiments of the charged internal combustion engine are therefore
also advantageous in which the support is adjustable in
continuously variable fashion between the first working position
and the rest position. That is to say that all positions between
the first working position and the rest position constitute further
working positions.
Embodiments are advantageous in which the support may be
electrically, hydraulically, pneumatically, mechanically or
magnetically controlled, preferably by means of the engine
controller of the internal combustion engine.
Embodiments of the charged internal combustion engine are
advantageous in which the at least one tongue-like element is
formed integrally with the support, and the support and the at
least one tongue-like element form a monolithic component.
A connection is provided, that is to say produced, between the
support and the at least one tongue-like element. Said connection
may be realized either by virtue of the two components being
manufactured in one piece, that is to say integrally, as per the
embodiment above, or alternatively by means of a cohesive,
non-positively locking or positively locking connection of the two
components.
The embodiment as a monolithic component eliminates the need for
connecting means such as screws, rivets or the like for forming a
connection. The design requirement for providing installation space
for the connecting means is thus also omitted.
Furthermore, the number of components is reduced significantly if
the support and the at least one tongue-like element are formed as
a monolithic component. Owing to the fact that fewer components
have to be manufactured and connected, less assembly and/or
production errors occur. This has an advantageous effect on
functionality and on service life.
As already mentioned above, however, embodiments of the charged
internal combustion engine may also be advantageous in which the
support and the at least one tongue-like element constitute
separate components that are connected to one another.
Embodiments of the charged internal combustion engine are
advantageous in which the multi-channel segmented turbine is a
dual-flow turbine with two channels.
In the case of a dual-flow turbine, two channels are arranged one
on top of the other as viewed in a section perpendicular to the
axis of rotation of the at least one rotor, wherein the two
channels enclose the at least one rotor in spiral form at different
radii at least along an arc-shaped section.
In the case of a dual-flow turbine, embodiments of the charged
internal combustion engine are advantageous in which the two
channels are open toward the at least one rotor in each case along
a circular-arc-shaped segment of 180.degree.. Then, the two
channels supply exhaust gas to the at least one rotor over
equal-sized circular arcs along the rotor circumference.
In conjunction with a dual-flow turbine, embodiments of the charged
internal combustion engine are advantageous in which the support
has two tongue-like elements which, when the support is in the
first working position, each lengthen the free tongue-like end of
one of a total of two housing walls that separate the two adjacent
channels from one another.
In the case of a dual-flow turbine, the two channels situated one
on top of the other are separated from one another by a housing
wall running in the interior of the turbine housing, wherein the
housing wall that delimits the housing to the outside commonly
separates the channels in the inlet region of the turbine, that is
likewise constitutes a housing wall that separates two adjacent
channels from one another. It is then necessary to provide two
tongue-like elements in order for the two housing walls to be
lengthened when the support is in the first working position.
In this connection, embodiments of the charged internal combustion
engine may however also be advantageous in which the support has
one tongue-like element which, when the support is in the first
working position, lengthens the free tongue-like end of one housing
wall that separates the two adjacent channels from one another. In
individual cases, the housing wall that delimits the housing to the
outside does not serve to separate the channels, such that the
housing wall running in the interior of the turbine housing
constitutes the only housing wall that separates two adjacent
channels from one another.
Embodiments of the charged internal combustion engine in which the
support has the same number of tongue-like elements as the turbine
comprises channels, or embodiments in which the support has one
tongue-like element fewer than the turbine comprises channels, are
basically advantageous.
Embodiments of the charged internal combustion engine are
advantageous in which the at least one housing wall is an immovable
wall that is fixedly connected to the housing. Said embodiment of
the housing wall better enables that the heat introduced into the
housing wall by the hot exhaust gas is discharged into and via the
housing in an advantageous manner and to an adequate extent.
Embodiments of the charged internal combustion engine are
advantageous in which the exhaust lines of the cylinders of each
cylinder group merge to form a respective overall exhaust line,
thus forming an exhaust manifold, within the cylinder head.
The multi-channel turbine provided in the exhaust-gas discharge
system may then be arranged very close to the outlet of the
internal combustion engine, which is to say close to the outlet
openings of the cylinders. This has several advantages, in
particular because the exhaust lines between the cylinders and the
turbine are shortened.
Not only is the path for the hot exhaust gases to the turbine
shortened, but both the volume of the individual exhaust manifolds
and the volume of the exhaust-gas discharge system downstream of
the turbine are also reduced. The thermal inertia of the
exhaust-gas discharge system is likewise reduced as a result of the
reduction of the mass and the length of the exhaust lines in
question.
In this way, the exhaust-gas enthalpy of the hot exhaust gases,
which is determined significantly by the exhaust-gas pressure and
the exhaust-gas temperature, may be utilized optimally, and a fast
response behavior of the turbine better enabled.
The proposed measure also results in a compact design of the
cylinder head and thus of the internal combustion engine according
to the present application, and permits dense packaging of the
drive unit as a whole.
The shortening of the line lengths and the associated reduction in
size of the exhaust-gas volume upstream of the rotor improves the
response behavior of the turbine and assists the pulse charging in
the low load and engine speed range.
The second sub-object on which the present application is based,
specifically that of specifying a method for operating a charged
internal combustion engine of a type described above, is achieved
by means of a method in which the support is transferred into the
first working position in order to increase the degree of
separation of the at least two channels by reducing the tongue
spacing.
That which has been stated in connection with the internal
combustion engine according to the present application likewise
applies to the method according to the present application.
Method variants are advantageous in which the support is
transferred into the first working position in order to assist
pulse charging.
Method variants are advantageous in which the displacement of the
support is performed in characteristic-map-controlled fashion.
Method variants are advantageous in which the support is
transferred into the rest position toward high loads and/or toward
high engine speeds.
An example engine with a turbocharger for charging is illustrated
in FIG. 1. An example turbocharger is shown in more detail in FIGS.
2, 3a, 3b, 3c, and 3d, such that the support affecting the
aerodynamic flow through the turbine may be examined. An example
support is shown in FIGS. 4a and 4b. An example method is outlined
in FIG. 5 for adjusting the support in response to an engine speed
and load. With this turbocharger configuration, it may be possible
to extend the operating range of the turbocharger.
FIG. 1 shows an example of a multi-cylinder engine 100 with a
turbocharger. As a non-limiting example, engine system 100 can be
included as part of a propulsion system for a passenger vehicle.
Internal combustion engine 100 may comprise a plurality of
cylinders, one cylinder of which is shown and is controlled by
controller 12. Engine 100 includes combustion chamber 30 with
cylinder walls 32 and piston 36 positioned within and connected to
crankshaft 40. Controller 12 is shown as a microcomputer including
microprocessor unit CPU 102, input/output ports I/O 104, an
electronic storage medium for executable programs and calibration
values shown only as read only memory chip ROM 106 in this
particulate example, random access memory RAM 108 and keep alive
memory KAM 110.
Controller 12 receives various signals from sensors coupled to
engine 100, including but not limited to: measurements of inducted
mass air flow (MAF) from mass air flow sensor 120; engine coolant
temperature (ECT) from temperature sensor 112 coupled to cooling
sleeve 114; a measurement of manifold pressure (MAP) from manifold
pressure sensor 122; throttle position (TP) from a throttle
position sensor 58; and a profile ignition pick up signal (PIP)
from Hall effect sensor 118 coupled to crankshaft 40 indicating an
engine speed. Engine speed signal, RPM, may be generated by
controller 12 from PIP signal. Manifold pressure signal MAP from a
manifold pressure sensor may be used to provide an indication of
vacuum, or pressure, in the intake manifold. Note that various
combinations of the above sensors may be used, such as a MAF sensor
without a MAP sensor, or vice versa.
Storage medium read-only memory chip 106 can be programmed with
computer readable data representing instructions executable by
processor 102 for performing the methods described below as well as
other variants that are anticipated but not specifically listed.
The controller 12 may receive input data from the various sensors,
process the input data, and trigger the actuators in response to
the processed input data based on instruction or code programmed
therein corresponding to one or more routines. An example control
routine is described herein with regard to FIG. 4.
Combustion chamber 30 communicates with intake manifold 44 and
exhaust manifold 48 via respective intake valve 52 and exhaust
valve 54. In the depicted example, the intake valve 52 is operated
by an intake cam 51 and the exhaust valve 54 is operated by an
exhaust cam 53. The position of intake valve 52 and exhaust valve
54 may be determined by valve position sensors 55 and 57,
respectively. In alternative embodiments, the intake and/or exhaust
valve may be controlled by electric valve actuation. For example,
cylinder 30 may alternatively include an intake valve controlled
via electric valve actuation and an exhaust valve controlled via
cam actuation including CPS and/or VCT systems. In still other
embodiments, the intake and exhaust valves may be controlled by a
common valve actuator or actuation system, or a variable valve
timing actuator or actuation system.
Each cylinder 30 of engine 100 may include a spark plug 92 for
initiating combustion. Ignition system 88 can provide an ignition
spark to combustion chamber 30 via spark plug 92 in response to
spark advance signal SA from controller 12, under select operating
modes. However, in some embodiments, spark plug 92 may be omitted,
such as where engine 100 may initiate combustion by auto-ignition
or by injection of fuel, as may be the case with some diesel
engines.
Each cylinder of engine 100 may be configured with one or more fuel
injectors for providing fuel thereto. As a non-limiting example,
cylinder 30 is shown including one fuel injector 66. Fuel injector
66 is shown coupled directly to cylinder 30 for injecting fuel
directly therein in proportion to the pulse width of signal FPW
received from controller 12 via electronic driver 68. In this
manner, fuel injector 66 provides what is known as direct injection
of fuel into combustion chamber 30. In FIG. 1, the fuel injector 66
is illustrated as a side injector, however, it may be located
overhead of the piston, such as near the position of spark plug 92.
Alternatively, the injector may be located overhead and near the
intake valve to improve mixing. In an alternate embodiment,
injector 66 may be a port injector providing fuel into the intake
port upstream of cylinder 30. In yet another embodiment, a port
injector and a direct injector may be provided. Fuel may be
delivered to fuel injector 66 from a fuel system (not shown)
including fuel tanks, fuel pumps, and a fuel rail.
Cylinder 30 may receive intake air via a series of intake passages
42, 46, and 44. Intake air passage 44 can communicate with other
cylinders of engine 100 in addition to cylinder 30. A throttle 62,
including a throttle plate 64, may be provided along an intake
passage of the engine for varying the flow rate and/or the pressure
of intake air provided to the engine cylinders. For example,
throttle 62 may be disposed downstream of compressor 162 as shown
in FIG. 1, or be provided upstream of compressor 162.
Exhaust passage 48 can receive exhaust gases from other cylinders
of engine 100 in addition to cylinder 30. Exhaust gas sensor 126 is
shown coupled to exhaust passage 48 upstream of emission control
device 70 and turbine 1. Sensor 126 may be any suitable sensor for
providing an indication of exhaust gas air/fuel ratio such as a
linear oxygen sensor or UEGO (universal or wide-range exhaust gas
oxygen), a two-state oxygen sensor or EGO, a HEGO (heated EGO), a
NOx, HC, or CO sensor. Emission control device 70 may be a
three-way catalyst (TWC), NOx trap, various other emission control
devices or combinations thereof.
FIG. 1 shows engine 100 configured with a turbocharger including a
compressor 162 arranged between intake passages 42 and 46, and an
exhaust turbine 1 arranged along exhaust passage 48. Compressor 162
may be at least partially powered by exhaust turbine 1 via shaft
161. The fresh air supplied to the cylinders of the engine 100 is
compressed in the compressor 162, which is driven by the turbine 1.
The turbine 1 is a multi-channel turbine and is further elaborated
in FIGS. 2-3.
FIG. 2 schematically shows a two-channel turbine 1, sectioned
perpendicularly to the axis of rotation 4 of the rotor 3 with an
annular support 5b. The two-channel turbine 1 is a two-channel
segmented turbine 11, also referred to as a dual-flow turbine 11.
The dual-flow turbine 11 has a turbine housing 2 in which a rotor 3
is mounted on a rotatable shaft 161. The dual-flow turbine 11 is
characterized by the fact that the two channels 8, 9 are arranged
one on top of the other, enclose the rotor 3 in spiral form at
different radii at least along an arc-shaped segment, and are open
toward the rotor 3 in each case along a circular-arc-shaped
segment. The two inlet openings 6, 7 of the dual-flow turbine 11
are arranged in a flange 10 of the housing 2, wherein each inlet
opening 6, 7 are adjoined by one channel 8, 9 of the turbine 1.
Each channel 8, 9 of the turbine 1 is connected to one overall
exhaust line of the internal combustion engine (not illustrated).
The two adjacent channels 8, 9 are separated from one another, in a
continuation of the overall exhaust lines in the turbine housing 2,
by means of a housing wall 5, wherein, at the rotor side, the
housing wall 5 has a free tongue-like end 5a. In addition to said
housing wall 5 that runs in the interior of the turbine housing 2,
the turbine 1 has a further housing wall 16 that separates the
channels 8, 9 from one another in the inlet region of the turbine 1
and which, at the rotor side, likewise has a free tongue-like end
5a.
The annular support 5b has at least one tongue-like element 5c; the
support 5b shown in FIG. 2 comprises two tongue-like elements 5c.
The support 5b is situated laterally adjacent to the rotor 3 and is
displaceable in a translational fashion along the rotatable shaft
161. The displacement of the support 5b between a first working
position and rest position, which are elaborated in FIG. 3, brings
the tongue-like elements to be abutted to the free tongue-like end
5a or to be hidden in the housing. Thus, the displacement of the
support 5b influences the degree of separation behavior of the
turbine channels by varying a tongue spacing. A switch 15 is
provided which displaces the support 5b in a translational fashion.
The switch 15 may be electrical, hydraulic, pneumatic, mechanic,
etc. and be controlled by controller 12.
The free tongue-like end 5a is in a fixed position as it is formed
at the end of the housing wall 5. There are two free tongue-like
ends 5a in the dual flow turbine, as shown. In other examples,
turbines with more or fewer channels may have more or less free
tongue-like ends. The annular support 5b includes tongue-like
elements 5c which are capable of being brought into alignment with
the free tongue-like ends 5a of the housing wall 5. In the rest
position, the tongue-like elements are withdrawn into the turbine
housing 2 by displacing the annular support in translational
fashion along the axis of rotation. Thus, the two channels have a
degree of interaction when the annular support 5b is in the rest
position. In the first working position, the tongue-like elements
5c are brought into alignment with the free tongue-like ends 5a
thereby lengthening the free tongue-like end of the housing wall.
Thus, the two channels have a lower degree of interaction in
comparison to the rest position.
FIG. 3a schematically shows the two-channel turbine 1 of a first
embodiment of the charged internal combustion engine, sectioned
perpendicularly to the axis of rotation 4 of the rotor 3, and with
a support 5b situated in the rest position. The turbine 1 is a
dual-flow turbine 11 as described in FIG. 2.
The two adjacent channels 8, 9 are separated from one another, in a
continuation of the overall exhaust lines in the turbine housing 2,
by means of a housing wall 5, wherein, at the rotor side, the
housing wall 5 has a free tongue-like end 5a and ends with a
spacing to the rotor 3, such that a tongue spacing .DELTA.r is
formed, with the result that a flow transfer duct is formed between
the channels 8, 9.
In the rest position illustrated in FIG. 3a, the support 5b is
situated laterally adjacent to the rotor 3. This is shown in FIG.
3b, which schematically shows the turbine 1 illustrated in FIG. 3a
in a section rotated through 90.degree. with respect to FIG. 3a.
The shaft 161 connects the turbine 1 the compressor 162 of the
turbocharger along the axis 4.
The support 5b is annular, has two tongue-like elements 5c and, for
the purpose of varying the tongue spacing .DELTA.r, is displaceable
in translational fashion (double arrow) along the rotatable shaft
161. In the rest position illustrated, the two tongue-like elements
5c, like the support 5a itself, are also positioned laterally
adjacent to the rotor 3. The rest position of the annular support
5b results in the flow transfer duct at the free tongue-like end 5a
of the housing wall 5 being open.
In the rest position, the support 5b and the tongue-like elements
5c are positioned such that they are within the housing. Thus, the
free tongue-like end 5a has a tongue spacing .DELTA.r, which is
larger than the first working position tongue spacing .DELTA.r1,
illustrated in FIG. 3c. The rest position decreases the degree of
separation behavior of the turbine channels with respect to the
first working position, which is illustrated further in FIGS. 3c
and 3d. The support in the rest position increases the degree of
interaction between the turbine channels. Put another way, the rest
position opens a flow transfer duct.
FIGS. 3c and 3d schematically show the turbine 1 illustrated in
FIG. 3a, with the support 5b in the first working position, wherein
FIG. 3c shows a section perpendicular to the axis of rotation 4 of
the rotor 3, and FIG. 3d shows a section rotated through 90.degree.
with respect to FIG. 3c.
It is sought to explain only the differences in relation to FIGS.
3a and 3b, for which reason reference is otherwise made to FIGS. 3a
and 3b and the associated description. The same reference symbols
have been used for the same components.
The support 5b that has been transferred into the first working
position by translational displacement for the purpose of varying
the tongue spacing, lengthen(s) the two housing walls 5 at the free
tongue-like end that separate the channels 8, 9 from one another,
whereby the tongue spacing .DELTA.r1 is reduced in each case. It is
sought for the support 5b to be integrated in as gas-tight a manner
as possible when in the first working position. The first working
position increases the degree of separation behavior of the turbine
channels by lengthening the free tongue-like end 5a by abutting the
tongue-like element 5c against the free tongue-like end 5a of the
housing wall 5. The degree of interaction of the two channels is
decreased and the flow transfer duct, which is open when the
support 5b is in the rest position, is now closed in the first
working position.
The illustrated dual-flow turbine 11 has two housing walls 5 which
separate the two channels 8, 9 and which may be lengthened,
specifically a housing wall 5 that runs in the interior of the
turbine housing 2, and the housing wall 5 which delimits the
housing 2 to the outside and which separates the channels 8, 9 from
one another in the inlet region of the turbine 1. In this respect,
the support 5b has two tongue-like elements 5c in order to lengthen
the two housing walls 5 at their free tongue-like ends 5a when the
support 5b is in the first working position.
FIGS. 4a and 4b illustrate the annular support 5b with at least one
tongue-like element 5c. In this example, two tongue-like elements
5c are illustrated. In another example, the annular support 5b may
have one tongue-like element. In yet another example, the annular
support 5b may have as many tongue-like elements 5c as there are
channels in the turbine. The annular support 5b is a ring shape and
moves in a translational fashion (double arrow) along the axis of
rotation 4. The annular support 5b and tongue-like elements 5c may
be constructed in one piece, as illustrated in FIG. 4a, or as a
multi-piece construction, as illustrated in FIG. 4b.
The one piece construction, shown in FIG. 4a, may be realized by
forming all of the parts integrally. This eliminates the need for
any connecting means such as screws, rivets, welds, etc. for
forming a connection between the annular support 5b and the
tongue-like elements 5c.
In contrast, the multi-piece construction, shown in FIG. 4b, may be
realized by forming the parts in two or more pieces and then
joining the pieces together via connecting means 14. The connecting
means 14 may include screws, rivets, welds, etc. for forming a
connection between the annular support 5b and the tongue-like
elements 5c.
FIG. 5 illustrates an example method for adjusting an annular
support to influence to degree of interaction between the channels
of the turbine, and thus the separation behavior of the turbine
channels. Example method 500 adjusts the annular support in
response to engine speed and engine load over a threshold to either
open or close a flow transfer duct. This example method shows how
the annular support described in FIGS. 2 and 3 may be used to
extend the operating range of the turbocharger. In another example,
the annular support may be adjusted in response to the exhaust flow
rate.
At 502, the method may determine the engine operating conditions.
This may include engine speed, engine load, engine temperature,
exhaust flow rate, etc.
At 504, the method may determine if the engine speed is below a
threshold. At engine speeds greater than this threshold, better
enabling a constant exhaust-gas pressure to act on the turbine may
increase engine efficiency. Therefore, if the engine speed is not
below the threshold, the method may adjust the support to the rest
position to increase the flow cross section of the flow transfer
duct at 506 by displacing the support such that the tongue-like
ends are hidden in the housing. Here, the tongue spacing is based
on the fixed free tongue-like end of the housing wall, e.g. the
distance to the rotor from the free tongue-like end as shown in
FIG. 3a. Thus, the degree of interaction between the two turbine
channels is increased when the tongue-like element of the annular
support is moved into the housing to open the flow transfer
duct.
However, if the engine speed is lower than the threshold at 504,
the method may proceed to 508 and determine if the engine load is
less than a threshold. In one example, the load threshold may be
set based on the engine speed. At high engine loads, increasing the
degree of interaction between the turbine channels may increase
engine efficiency. If the engine load is not less than the
threshold at 508, the method may adjust the support to the rest
position at 506 as described above. Thus, a degree of separation
between the two channels is decreased when the tongue-like
element(s) of the support is hidden in the housing.
If the engine load is less than the threshold at 508, the method
may adjust the support to the first position to decrease the flow
cross section of the flow transfer duct at 510. Adjusting the
annular support to the first position brings the tongue-like ends
to abut with the free tongue-like ends by displacing the annular
support in a translational manner along the rotatable axis from the
rest position to the first working position. The support in the
first working position lengthens the free tongue-like end of the
housing wall that separates two adjacent channels by bringing the
tongue-like element 5c into a position where it abuts against the
free tongue-like end, thereby lengthening the free tongue-like end
of the housing wall and decreasing the tongue spacing to the at
least one rotor, e.g. the distance to the rotor from the free
tongue-like end as shown in FIG. 3c. The translational movement of
the support along the axis of rotation from the rest position to
the first working position brings the tongue-like element from a
position within the housing into contact with the free tongue-like
end, thereby lengthening the free tongue-like end and reducing the
tongue spacing to the rotor. Moving the tongue-like element of the
annular support into an exhaust flow at the free tongue-like end of
the housing wall reduces the tongue spacing to the rotor in the
first working position.
Method 500 illustrated an example to adjust an annular support in a
two-stage fashion in response to engine speed and load. In other
examples, other operating parameters may be used to determine
adjustment of the annular support. Further, the annular support may
be adjusted in a continuously variable fashion, allowing for
greater control over the degree of separation of the two channels
by reducing a tongue spacing in a targeted manner.
Note that the example control and estimation routines included
herein can be used with various engine and/or vehicle system
configurations. The control methods and routines disclosed herein
may be stored as executable instructions in non-transitory memory.
The specific routines described herein may represent one or more of
any number of processing strategies such as event-driven,
interrupt-driven, multi-tasking, multi-threading, and the like. As
such, various actions, operations, and/or functions illustrated may
be performed in the sequence illustrated, in parallel, or in some
cases omitted. Likewise, the order of processing is not necessarily
required to achieve the features and advantages of the example
embodiments described herein, but is provided for ease of
illustration and description. One or more of the illustrated
actions, operations and/or functions may be repeatedly performed
depending on the particular strategy being used. Further, the
described actions, operations and/or functions may graphically
represent code to be programmed into non-transitory memory of the
computer readable storage medium in the engine control system.
It will be appreciated that the configurations and routines
disclosed herein are exemplary in nature, and that these specific
embodiments are not to be considered in a limiting sense, because
numerous variations are possible. For example, the above technology
can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine
types. The subject matter of the present disclosure includes all
novel and non-obvious combinations and sub-combinations of the
various systems and configurations, and other features, functions,
and/or properties disclosed herein.
The following claims particularly point out certain combinations
and sub-combinations regarded as novel and non-obvious. These
claims may refer to "an" element or "a first" element or the
equivalent thereof. Such claims should be understood to include
incorporation of one or more such elements, neither requiring nor
excluding two or more such elements. Other combinations and
sub-combinations of the disclosed features, functions, elements,
and/or properties may be claimed through amendment of the present
claims or through presentation of new claims in this or a related
application. Such claims, whether broader, narrower, equal, or
different in scope to the original claims, also are regarded as
included within the subject matter of the present disclosure.
* * * * *